CONTRAST MEDIA

Question 1

What are CONTRAST MEDIA (AGENTS)?

Answer 1

are substances which are added to the body during radiographic studies to visualize a specific part.

Question 2

WHAT ARE 5 RADIOGRAPHIC DENSITIES?

Answer 2

Air (gas)
Fat
Water
Mineral
Metal

Question 3

WHAT IS THE Purpose of contrast study?

Answer 3

To visualize anatomic structures that are not normally seen on a diagnostic medical image

Question 4

CONTRAST MEDIA

Answer 4

-Visualizes anatomy normally not seen

-Requires the administration of media(agent) into patient

-Requires attention to indications and contraindications

-Warrants serious attention to patient reactions

Question 5

Radiographic images without contrast media will have what type of contrast?

Answer 5

“low subject contrast” which means it will be difficult to the different areas within the body.

Question 6

Adding contrast media or a contrast agents will permit the visualization of organs and structures such as?

Answer 6

such as vessels that could not be visualized without the addition of contrast media.

Question 7

Two Types of Contrast Media

Answer 7

1. Negative
2. Positive

Question 8

When must a pre-test patient interview be done?

Answer 8

prior to all contrast studies to R/O the possibility of previous allergic reactions and to identify any medical conditions that the patient may have that may alter the procedure

-Such as asthma or diabetes.

Question 9

WHAT KIND OF FORM WILL PATIENTS BE REQUIRED TO SIGN?

Answer 9

Patients will be required to sign a consent form for all radiographic studies that will require the administration of contrast media.

Question 10

INFORMED CONSENT IS NEEDED FOR?

Answer 10

Usually for invasive procedures such as special procedures and IV contrast injection procedures and the instillation of a contrast agent other than orally or rectally.

The consent form is separate from the general admissions forms signed by the patient.

The patient must be of sound mind and legal age.

Consent must be signed by the parent or legal guardian for minors.

Adult patients may also have a legal guardian.

The patient must give consent freely (voluntarily).

The patient must be adequately informed about the procedure about to take place.

Explanation of the procedure must be in terms the patient understands.

Question 11

WHY IS A IMPLIED CONSENT NEEDED?

Answer 11

It Provides care when the patient is unconscious.

Based on the assumption that the patient would approve if able or conscious.

Even with a signed consent, if during a radiographic exam, the patient decides to stop a radiographic procedure (with or without contrast) the radiographer must stop the exam as soon as it is safe to do so.

Question 12

Radiographer Responsibilities in the Administration of Contrast Media:

Answer 12

Know considerations

Knowledge of potential adverse reactions

Preparation of patient

Know indications

Preparation of contrast material(s).

Patient education and support

Obtain patient consent

Obtain and record patient history

Record the patient’s BUN and Creatine levels.

Monitor patients throughout exam.

Question 13

JCAHO (Joint Commission on Accreditation of Healthcare Organizations) Medication Management Standard

Answer 13

All contrast agents (i.e., iodinated for injection and Oral Barium) are consideration medications.

Each contrast agent must have a written order for the drug to be administered and the contrast agents must be handled in accordance with the protocol for any prescription medication.

This includes having a written order and a thorough medication and health history. Many other prescription and over-the-counter drugs may interact with or have contraindications to the contrast agents.

Question 14

WHAT ARE THE TYPES OF CONTRAST MEDIA?

Answer 14

-NEGATIVE
-POSITIVE
-SPECIALTY CONTRAST AGENTS

Question 15

NEGATIVE

Answer 15

Radiolucent – (negative) contrast agents transmit x-rays.

Negative contrast agents are
- air and carbon dioxide.

Negative contrast agents are composed of elements with low atomic number.

Negative contrast agents will appear dark on radiographs.

Question 16

When do negative contrast agents combine with a positive contrast?

Answer 16

Negative contrast agents may be combined with positive contrast agents
(i.e. air added to barium)

(To produce double-contrast studies)

Question 17

NEGATIVE

Answer 17

• Air and Carbon dioxide
• May be used by themselves or combined with a positive contrast

The atomic number of Hydrogen is 1.

The atomic number of carbon Dioxide is 6.

The atomic number of Oxygen is 8.

Question 18

Complications of using negative contrast:

Answer 18

-Embolus (air injected into the bloodstream)

-Because of the risk of air emboli, negative contrast media is never introduced (injected) into the blood stream.

-Joint distention, pain will occur after the injection of air into the joint space

Question 19

POSITIVE ( BARIUM)

Answer 19

Radiopaque – (positive) contrast absorbs x-rays

Positive contrast agents are composed of elements with high atomic numbers
.
Positive contrast agents will appear whit on radiographs

Question 20

Specialty Contrast Agents

Answer 20

ULTRASOUNDS
-MICROBUBBLES

MR SCANNING
-gadolinium-DTPA.

those agents used for specialty exam such as MRI and Sonography

MRI – the contrast agent most often used is gadolinium-DTPA.

US – the contrast agent most often used is gas-filled micro bubbles.

Specialty contrast agents such as gadolinium diethylenetriaminepentaacetic acid (gadolinium-DTPA) used in MRI

Question 21

Why Is Air Not Used More Often as a Contrast Material?

Answer 21

Low Persistence

Question 22

Perfect Contrast Material

Answer 22

• Very–high-contrast visualization
• Extremely low toxicity to patient
• Persistence in patient anatomy until imaging is completed
• Low cost
• Minimal or no side effects

Question 23

KEY CONTRAST CHARACTERISTICS

Answer 23

Ability of agent to mix with body fluids

Viscosity - the thickness of a liquid or resistance to the flow of a contrast agent.

Ionic strength

Persistence in the body

Iodine content

Potential for toxicity

Osmolality

Question 24

Osmolality

Answer 24

is the measurement of the number of particles in a solution per kilogram of water.

Contrast agents have osmolalities much higher than those of other body fluids.’

Most allergic reactions occur with contrast agents that have high osmolality.

Question 25

Osmosis

Answer 25

the process by which water moves from an area of greater concentration to an area of lesser concentration.

Question 26

Viscosity

Answer 26

describes the thickness of a liquid or resistance to the flow of a contrast agent. (Viscosity (thickness) may be significantly reduced by warming the solution to near body temperature.) Contrast agents are also highly viscous (thick and Sticky).

Question 27

Common Contrast Choices

Answer 27

1. BARIUM SULFATE 2. AIR/GAS (CO2) 3. OIL-BASED IODINE CONTRAST AGENT 4. WATER SOLUBLE CONTRAST AGENT

Question 28

CONTRAST MEDIA CHOICES

Answer 28

BARIUM- 56 IODINE-58 AIR/GAS- AVERAGE Z#8 The atomic number of Hydrogen is 1. The atomic number of carbon Dioxide is 6. The atomic number of Oxygen is 8.

Question 29

Barium sulfate (INERT SALT)

Answer 29

POSITIVE CONTRAST Barium is the commonly used contrast medium used to visualize the GI tract.' Barium is an inert compound radiopaque substance. The atomic number of BaSO4 is 56. Barium mixed with water is a suspension. -Push fluid following barium studies

Question 30

BARIUM

Answer 30

High atomic number enhances the photoelectric effect. Chemically inert Insoluble in water Tends to flocculate in acid pH Contraindicated in cases of bowel perforation Typically mixed with flavors, coloring, and so on to improve palatability Hypervolemia must be considered in colon examinations.

Question 31

Barium Studies of the GI Tract

Answer 31

Be aware of extravasation of barium in suspected cases of bowel perforations - CHANGE TO iodine if contraindicated

Question 32

COMPLICATIONS OF BARIUM

Answer 32

-Barium is contraindicated if there is a perforation of the digestive tract. -Barium cannot be absorbed into the body. -Peritonitis may occur if barium enters the pelvic or peritoneal cavity. The barium will need to be surgically removed. -

Question 33

Complications of Barium

Answer 33

Barium may pass into the peritoneal cavity or bloodstream through a break in the mucosa. In place of barium a water soluble iodine contrast will be used such as Gastrographin. Barium Peritonitis is an extravasation of BaSO4 into the abdominal cavity.

Question 34

Aspiration

Answer 34

inhalation of BASO4 into the lungs during a UGI, Esophagram or Small Bowel Series may occur if the patient aspirates during the procedure.

Question 35

Allergic Reaction

Answer 35

allergies to BASO4 are rare but may occur and are usually caused by the additives to the barium. Over-inflation of the retention balloon of the enema catheter (tip) may cause perforation of the rectum or colon. Latex enema tip allergy. Patients must be screened from possible latex allergies. Nonlatex enema tips are available.

Question 36

Constipation

Answer 36

patients should be instructed to drink plenty of water for a few days following an exam in which BASO4 is used. The main symptom of obstruction of the colon is constipation.

Question 37

WATER SOLUBLE IODATED CONTRAST AGENTS

Answer 37

IONICS VS NONIONICS

Question 38

IONIC CONTRAST AGENTS

Answer 38

Uses iodine as the contrast material Dissociates into two ions: Anion and Cation Viscosity Osmotic effects Dehydrated patients are vulnerable to hypovolemic shock. Be aware of concentration of molecular particles in contrast agent.

Question 39

IONIC CONTRAST AGENTS

Answer 39

The higher the iodine concentration, the greater the risk of adverse reactions. Any contrast agent that contains iodine increases the risk for anaphylactic reactions. Iodine has an atomic number of 53 which means iodine is a radiopaque substance. Examples of Iodinated Contrast Agents: Hypaque Renografin

Question 40

OIL BASED IONIC CONTRAST AGENTS

Answer 40

Insoluble in water High viscosity – oil based iodinated contrasts do not flow easily through the syringe. Oil based contrast agents are used infrequently in radiography. Oil based contrasts are used for i.e. Bronchography and Lymphography.

Question 41

OIL BASED CONTINUE

Answer 41

Store in a cool, dark area. When exposed to air, heat, and light the contrast breaks down or decomposes. Do not use it if a color change occurs, should be a pale yellow or amber. A dark color change indicates a decomposition of the contrast material. Use only glass syringes, not plastic. Toxic substances from plastic syringes may dissolve into the Oil-based contrast.

Question 42

ANAPHYLACTOID REACTIONS

Answer 42

Urticaria Wheezing Throat swelling (edema) Bronchospasm Nausea Vomiting Cardiac arrest It is critical to take a thorough patient history when contrast media is a part of any examination

Question 43

NONIONIC CONTRAST AGENTS

Answer 43

Do not dissociate into anions and cations Water soluble No ionic breakdown and less toxic at the cellular level Warmed to increase viscosity High contrast effect resulting from number of iodine atoms per molecule Reduced injection volumes

Question 44

NON IONIC CONTINUE

Answer 44

Also called lower-osmolality contrast media. They cost two to three times more than iodinated contrasts but are less likely to cause allergic reactions. More tolerable by patients Examples of Non-Iodinated Contrast Agents: Isovue Omnipaque Ultravist

Question 45

Non-Iodinated Contrast agents are used when patients have:

Answer 45

Hx of adverse reactions to contrast Hx of asthma or allergies Known cardiac problems Diabetes mellitus Renal disease Sickle cell disease Elevated creatine levels Patients that will have a Helical CT Patients at increased risk for reactions should receive nonionic contrast agents.

Question 46

Contrast Considerations

Answer 46

Patient history Renal function Contrast cost Metformin (Glucophage) should be discontinued for 48 hours before and 48 hours after the use of iodine contrast media. Contrast-enhanced CT studies

Question 47

Contrast Reactions

Answer 47

Generally, occur within the first minute of injection Can be unpredictable Mild reaction may worsen to severe at any time. Reaction is different from a side effect. Monitor patient continually.

Question 48

Types of Reactions to Contrast Media

Answer 48

Minor Reactions Rash, Hives (urticaria) Vomiting, Nausea Cough Itchy palms/soles Metallic or altered taste Warmth, heat Headache Dizziness Shaking Pallor Flushing of the skin Chills, sweats Nasal stuffiness Swelling, eyes and face Anxiety

Question 49

Vasovagal Reaction

Answer 49

Sudden episodes of hypotension and fainting that may occur during a radiographic procedure induced by the response of the nervous system to abrupt emotional stress, pain, or trauma. The Vasovagal nerve becomes overstimulated, and the patient may become extremely lightheaded and may pass out. The Vasovagal reaction is also called a Vasovagal attack.

Question 50

Radiographers Response to a Vasovagal Reaction (Syncope)

Answer 50

Check the person’s airway, breathing and circulation. If necessary, call a code and begin rescue breathing and CPR. Loosen tight clothing around the neck. Keep the affected person lying down for at least 10-15 minutes, preferably in a cool and quiet space. If the person cannot lie down, have him sit forward and lower his head below the levels of the shoulders, between the knees. If the person has vomited, turn him or her to one side to prevent choking and aspiration. Elevate the feet above the level of the heart (about 12 inches).

Question 51

Moderate (intermediate) Reactions

Answer 51

Respiratory Tachycardia/Bradycardia Hypotension Hypertension Persistent hives Facial swelling Dyspnea Bronchospasm, wheezing Laryngeal edema

Question 52

Severe Reactions

Answer 52

Convulsions Laryngeal edema Severe respiratory symptoms Severe hypotension Cardiac arrhythmia’s Shock Unconsciousness, unresponsiveness Cardiopulmonary Arrest

Question 53

Radiographer response to Severe Reactions:

Answer 53

Immediately obtain medical assistance. Inform the radiologist or MD of any reactions that the patient is having from the contrast agent. Clinical findings will indicate the need for immediate medical treatment including drug therapy.

Question 54

Treatment of Severe Reactions

Answer 54

Maintain an open airway Maintain an open IV Monitor vital signs Antihistamines are used to counteract hives and urticaria. Blood pressure must be monitored and the patient should be checked for heart irregularities. CPR as indicated by patient’s condition.

Question 55

Scheduling of Exams (requiring contrast media administration)

Answer 55

1. All exams without contrast should be scheduled first. 2. Ultrasounds exams are scheduled before barium studies 3. Studies involving intra-vascular contrast are done before Barium Studies 4. "BE" exams are performed before UPPER GI STUDIES 5.Exams that require patients to fast before the exam should be scheduled in the morning.

Question 56

Fasting Instructions for Patients with Diabetes

Answer 56

Diabetic patients are at risk for changes to their blood sugar if they fast for a radiographic exam. All diabetic patients should obtain instruction from their referring MD whether they are to take their usual dose of insulin or other diabetes medication on the day of the exam. All diabetes patients may be closely observed for rapidly developing symptoms of hypoglycemia and hyperglycemia. Non-insulin dependent diabetic patients that are taking the medication Glucophage (Metformin) will be instructed by their referring MD to discontinue the Glucophage for 48 hours after a radiographic contrast exam using an iodine contrast media.

Question 57

SEQUENCE OF RADIOGRAPHIC CONTRAST EXAMS

Answer 57

1st IVP 2nd GB 3rd BE 4th GI

Question 58

RADIOGRAPHIC CONTRAST EXAMS THAT MAY BE PERFORMED TOGETHER

Answer 58

GB and IVP IVP and BE GB and GI 2-1 1-3 2-4

Question 59

LAB TESTS PRIOR TO CONTRAST ADMINISTRATION

Answer 59

Two lab (blood) tests should be done before contrast exams to determine renal function. Renal function is important because contrast media is filtered through the kidneys.

Question 60

BUN – blood urea nitrogen

Answer 60

BUN provides information about kidney function and the ability of the kidneys to remove impurities from the body. BUN normal values range between 5 to 25 mg/dl.

Question 61

Creatine

Answer 61

Creatine – creatine is a waste product stored in the muscles. Elevated creatine levels indicate impairment of the function of the kidneys. Creatine normal values range between 0.6 to 1.7 mg/dl

Question 62

SCREENING FOR CONTRAST AGENTS

Answer 62

The radiographer must ascertain and report to the radiology nurse and radiologist the following: If the patient has had any prior reactions to a contrast agent or radiology procedure. If the patient has any known allergies to iodine, barium, latex or shellfish. If the patient has any of the following pre-existing medical conditions: Hypertension Asthma Sickle cell anemia Renal impairment Diabetes The radiographer’s responsibilities (i.e. obtaining consent, taking a patient history, documentation, screening, preparing the contrast agents etc.) will depend on institutional policy.

Question 63

PATIENT PREPARATION FOR RADIOGRAPHIC CONTRAST EXAMS

Answer 63

The patient should be given pre-procedural instructions at the time that the appointment for the contrast exam is made.   Pre-procedural Instructions   IVP NPO after midnight Cleansing enemas Empty bladder before scout film

Question 64

PATIENT PREPARATION FOR RADIOGRAPHIC CONTRAST EXAMS

Answer 64

  GB Patient takes prescribed iodinated contrast (tablets) the evening before scheduled exam Evening meal is fat free to prevent gallbladder contraction Water only in the morning of the exam   BE Cathartics (laxatives) as prescribed by MD Low residue diet Cleansing enemas   UGI NPO after midnight

Question 65

Radiopharmaceuticals

Answer 65

-Not contrast agents -Radioactive material chemically attached to a pharmaceutical that is metabolized in the body -Biodistribution is important -Typically emit gamma radiation -Detected by gamma camera in the nuclear department -Effective for cellular physiology assessment -Contamination and spillage of critical importance

Question 66

Handling Radiopharmaceuticals

Answer 66

Time is of the essence. Be aware of contaminations. Contaminations can produce image artifacts. Contaminations increase exposure unnecessarily to patients and personnel. Two types of contamination: External Internal

Question 67

Health Professional Responsibilities When Administering Contrast Agents

Answer 67

Administered under the supervision of a licensed physician with proper qualifications Patient assessment and history Patient comfort and education Recognize signs and symptoms of reaction and act appropriately. Patient care and surveillance Post exam considerations for patient Remain calm and reassuring during procedures.

Question 68

CONCLUSION

Answer 68

Contrast materials are an indispensable part of medical imaging. Classified as positive or negative Rely on the photoelectric effect for contrast visualization Iodine-based contrast media can cause anaphylaxis. Nonionic, low-osmolality contrast agents have reduced patient reactions but still a reality of imaging. Radiopharmaceuticals are used to assess cellular physiology (perfusion) . Patient reactions and care are constant responsibilities of the radiologic sciences professional.